Hand hole forming method for cellular



Feb. 2l, 1956 J. HOSEASON 2,735,166

HAND HOLE FORMING METHOD FOR OEE u AR O FLOOR WIRE OISTRIEUTING sYsTE Filed Aug. e, 1955 IN V EN TUR. Harry J /sea san United States Patent O HAND HOLE FORMING METHOD FOR CELLULAR FLOOR WIRE DISTRIBUTING SYSTEMS Harry J. Hoseason, Toronto, Ontario, Canada Application August 6, 1953, Serial No. 372,666

2 Claims. (Cl, 29-467) This invention relates to cellular oor wire distributing systems and more particularly to hand hole forming method therefor.

In such systems, it is usual to provide Wire containing cells with ducts extending transversely of the cells. Each duct has communication with one or more of the cells over which it passes and access to the duct from the floor surface must be provided. Usually, a floor covering, such as linoleum is laid directly over the ducts and, While the location of the ducts is known, it will be apparent that accurate measurements are necessary before cutting through the oor covering to produce a hand hole in any chosen duct.

It is an object of this invention to provide a method for quickly, accurately and neatly producing hand holes in covered ducts for floor wire distributing systems.

This invention will be described with reference to the accompanying drawing, in which Figure 1 is a perspective view of a portion of a cellular iloor structure embodying the present invention,

Figure 2 is a partial transverse sectional elevation of a duct and related structure, and

Figure 3 is a partial transverse sectional elevation of a duct and related floor structure, with a hand hole formed therein.

In the drawing, the floor is shown as constructed of preformed concrete slabs 1 having wire receiving cells 2 therein. Crossover metal ducts 3 are provided in transverse relation to the cells 2. Each duct has bottom openings 4 each communicating with a complementary opening 5 in the slab 1 leading to a respective cell 2. A metal grommet 6 preferably lines the wall of the communicating openings, such grommet having a lower edge head 7 and an upper rounded edge flange 8 engaging the duct, such rounded edges permitting ease of movement of Wires through the grommet while preventing injury to the wires.

Knockouts 9 are provided in the upper wall of the duct 3, each knockout having a diameter approximately equal to that of the desired hand hole. Each knockout is formed in the usual manner by partially severing the wall of the duct along the line 10. Mounted axially in each knockout is a removable marker such as a grub screw 11.

The oor is provided with the customary top ill 12 of cementitious or like material, the upper surface of which is preferably tiush with that of the upper wall of duct 3. The floor covering 13 of linoleum or the like is then applied to the iloor as by the layer of adhesive 14.

With the head of the grub screw 11 in elevated position, as shown in Figure 2, the covering 13 is punctured to expose the head of the screw, which is adjusted to lie ilush with the surface of the covering.

When it is desired to provide a hand hole in the duct, a knockout 9 in the required location is immediately identitied by means of its marker 11. With the center of the knockout thus clearly determined, it is a simple matter to scribe a circle on the floor covering the exact size desired to form the required hand hole. Severing of the scribed covering disc and removal of the underlying knockout is then readily eifected.

A threaded peripheral ring 15 is preferably applied to the opening in the duct as by screws 16 or the like, such ring being adapted to receive a threaded cover disc 17, which may be conveniently removed and applied as desired. The disc 17 is preferably formed with a shallow circular recess 1S in its upper surface to receive a disc 19 of floor covering of complementary size.

I claim:

1. A method of forming a hand hole in a iloor duct concealed by a preformed floor covering which comprises identifying a circular knockout portion in said duct by applying a marker to the axis of said portion prior to laying of said floor covering puncturing said covering by the marker to provide a visible indication of the axis of said portion, said marker projecting upwardly from said knockout portion a distance not substantially greater than the thickness of the floor covering subsequently scribing a circle on said covering about said axis, and then removing the scribe-enclosed covering portion and the underlying knockout portion to form the hand hole and applying a separable hand hole cover structure to said hand hole.

2. A method of forming a hand hole in a oor duct concealed by a linoleum covering which comprises identifying a circular knockout portion in said duct by applying a grub screw to the axis of said portion prior to the laying of said linoleum covering, puncturing said covering by the grub screw to provide a visible indication of the axis of said portion, said screw projecting upwardly from said knockout portion a distance not substantially greater than the thickness of the lineolum covering, subsequently scribing a circle on said covering about said axis, removing the scribe-enclosed covering portion and the underlying knockout portion to form the hand hole, fixing a threaded ring to the periphery of said hand hole, applying to said ring a recessed, threaded cover disc and fixing in the recess of said cover disc, a portion of said linoleum covering to be substantially flush with the surface of said linoleum covering.

References Cited in the file of this patent UNITED STATES PATENTS 1,533,759 Richardson Apr. 14, 1925 2,113,675 Brown Apr. 12, 1938 2,266,610 Martin Dec. 16, 1941 2,594,810 Schaub Apr. 29, 1952 2,620,080 Tomlin Dec. 2, 1952 2,666,546 Reilly Jan. 19, 1954 

